District of Columbia Watershed Implementation Plan (WIP)

Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

Chesapeake Bay Program (CBP) Load Allocations

TN loads TP Loads

State E3 load Tributary Strategy load   State E3 load Tributary Strategy load

DC 1.47 2.26   DC 0.05 0.11

DE 2.31 3.16   DE 0.19 0.27

MD 28.05 39.84   MD 1.88 3.10

NY 6.55 9.55   NY 0.43 0.65

PA 62.70 75.70   PA 2.10 3.04

VA 39.39 55.66   VA 3.59 6.64

WV 3.71 4.80   WV 0.38 0.55

Total 144.19 190.96   Total 8.62 14.36

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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Chlorophyll a (Chl a) Problem Segments: DCPTF

Tidal Potomac does not meet District’s Chl a water quality standard

District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

Solutions:

1. Reduce allocation of Phosphorus and Nitrogen to E3 and beyond

2. Modify existing Chl a standard of 25mg/L with a variance allowing exceedances of Chl a at a percentage

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

Solution 1: Reduce allocation of Phosphorus and Nitrogen to E3 and beyond

Issues:

a) Even if E3 was implemented, compliance with standard may not be achieved

b) Possible reasons for variance may include practicality or cost

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

Solution 2: Modify existing Chl a standard of 25mg/L with a variance allowing exceedances of Chl a at a percentage

Issues:

a) EPA agreement

b) Support information gathering

c) Public Participation

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

EPA is conducting model runs to:

• ensure use of appropriate Chl a data

• DDOE will continue to work with CBP and EPA Region III staff to incorporate a viable solution into the District’s WIP

District of Columbia Watershed Implementation Plan (WIP)Blue Plains Regional Committee

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District Department of the EnvironmentWatershed Protection Divsion1200 First Street, NE 5th FloorWashington, DC 20002 Main Line: (202) 535-2600 green.dc.gov

Possible Next Steps:

1. Initiate the process for a variance

2. Work with EPA on development of District’s WIP

Restoration Variance (Maryland): “The percentage of allowable exceedance for restoration variances is based on water quality modeling and incorporates the best available data and assumptions. The restoration variances are temporary, and will be reviewed at a minimum every three years, as required by the Clean Water Act and EPA regulations. The variances may be modified based on new data or assumptions incorporated into the water quality model.”

The District of Columbia may pursue adopting a similar definition.

Possible approach

Questions